Marvel's Guardians of the Galaxy

As the game describes in an early tutorial, you can stagger enemies by filling up the white meter underneath their health, at which point they will glow a sort of orange color and be vulnerable to a lot of damage. This achievement requires you to stagger a cumulative total of 25 enemies.

This achievement is essentially progress related and can't be missed. While your allies do have abilities to stagger enemies, I unlocked this achievement very early in my playthrough without even trying. Some bosses require you to stagger them, and some abilities you'll be using, such as Groot's and Drax's, will stagger enemies immediately. Additionally, the Eye of the Hurricane ability that Quill has does an area of effect attack that automatically staggers all enemies around you. You will almost assuredly stagger more than enough enemies for this achievement before you even unlock that ability, but once you do unlock it and work on its achievement, you will end up staggering plenty more enemies.